Blood and other bodily fluids handled in large quantities by medical laboratories for processing and testing present cost containment and biohazard issues for the laboratory. In order to minimize costs of testing fluids, the equipment and procedures utilized to process such samples are becoming increasingly automated so as to permit the procedures to be performed as quickly as possible with minimum labor. Automating sample processing has the additional benefit of minimizing the handling of blood and other bodily fluids that are now classified as hazardous substances.
In order to analyze samples of patient fluids, including human blood, a sample must first be taken from the patient. Usually the sample is housed within a container to be aspirated from during analyzer operation. These sample containers are then loaded into an automatic sample analyzer. If the sample container is capped, the cap must first be removed before a sample can be aspirated for analysis. This can be done manually by the operator, or, if the sample container has a frangible seal, the analyzer may contain a piercing apparatus to break the seal on the container to allow aspiration of a fluid sample.
Currently available commercial sample analyzers capable of piercing sealed containers have several disadvantages that reduce the effectiveness and efficiency of the sampling and analysis operations. For example, some analyzers use the sample aspirator in a dual mode to break the frangible seal, as well as to aspirate sample. The use of the sample aspirator in the dual mode may cause blockage of the sample aspirator if fragments of the seal enter the tip of the aspirator or the venting apertures disposed on the sample aspirator. Additionally, even if a separate piercing apparatus is used to break the frangible seal, when the sample aspirator alone subsequently enters the perforated seal, debris from the seal can block the sample aspirator tip and/or any venting ports disposed thereon, thus reducing the accuracy of the sample volume aspirated, and potentially damaging the sample aspirator. Clogged venting ports and aspirator tips increase the risk of cross-contamination of patient samples and also require that more time be dedicated to cleaning of the apparatus, thus increasing throughput times and decreasing the effectiveness of the analyzer.
Furthermore, some analyzers use a piercing device that is separated from the sampling device. In some devices, the piercing device is located in close proximity to the sampling device; however, in some devices the piercing device and sampling device may be located in different areas of the analyzer. Consequently, additional time is required to first position the sample tube for piercing and to then either reposition the sample in relation to the sample aspirator, or to move the sample aspirator to the location of the sample vial. These movements increase the throughput time of the sample analyzer, thus decreasing its efficiency.
In addition, currently available sample analyzers may only be able to aspirate sample from one type of vial or sample container at a time. Consequently, if an operator had multiple samples in different sized vials, only similar containers could be processed in the same batch. A new cycle or additional analyzer calibration would be required for each style of vial present. The inability of a sample analyzer to process different sized vials in the same batch negatively affects the throughput time of the analyzer, decreasing its efficiency.
There is, therefore, a demonstrated need in the art for a more efficient automated sample analyzer with improved throughput rates and improved probe designs. The improved sample analyzer reduces or eliminates the problems associated with current devices used to pierce sample vial caps, reduces clogging of both the piercing and sampling mechanisms thereby reducing cross-contamination, improving the accuracy of aspirating sample volumes, and improves access to samples in a variety of differently sized sample tubes.